Method of securing a cavity using a rigid sheath with transparent cap

ABSTRACT

An endoscopic sheath comprising a tubular sheath section having a distal end portion and a hole which extends throughout the length of the sheath section and through which an insert section of an endoscope having observation device can be passed, at least the distal end of the distal end portion opening, and at least the distal end portion being formed of a transparent material, and positioning device for positioning the insert section of the endoscope in the sheath section so that at least part of the distal end portion of the sheath section can be within the view range of the endoscope. A method of securing a cavity includes introducing the sheath and transparent distal end portion into an incision and detaching first and second tissues using the sheath and transparent distal end portion.

This is a division of application Ser. No. 08/519,481 filed Aug. 25,1995, now U.S. Pat. No. 5,695,448.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscopic sheath used incombination with an endoscope for observing the interior of a bodycavity.

2. Description of the Related Art

Conventional sheaths to be fitted on the insert section of endoscopeshave various configurations depending on the purpose of application.

Described in Jpn. Pat. Appln. KOKOKU Publication No. 4-10328, forexample, is a sheath which enables a direct endoscopic observation ofsubcutaneous tissue or any other desired portion of a living body inwhich no spaces exist. This sheath is a rigid guide tube through whichan endoscope is passed and guided to a target region in a patient'sbody. The distal end of the sheath is closed, and at least part of it isformed of a material which transmits light. As this sheath is insertedinto subcutaneous tissue or other organic portion without spaces, itthrusts aside the organic portion, thereby positively creating a spacein the region. Thus, by passing the endoscope through the sheath kept inthe subcutaneous tissue, for example, the tissue can be subjected toendoscopic observation through the transparent guide tube portion.

Disclosed in Jpn. UM Appln. KOKOKU Publication No. 4-43202, moreover, isa tubular protective sheath which is fitted on an insert section of anendoscope to protect the endoscope. This sheath enables endoscopicobservation through its distal opening. A stopper for preventingprojection of the endoscope is provided on that part of the distal endportion of the sheath which does not interfere with the view range ofthe endoscope. The stopper can prevent the endoscope from projectingfrom the distal end of the sheath without the possibility of the distalend edge of the sheath or the like interfering with the view range ofthe endoscope. Thus, the entire view range can be utilized, and thedistal end portion of the endoscope can be prevented from being damaged.

The sheath used with the endoscope in this manner is expected tofacilitate accurate observation of the state of a subject tissue bymeans of the endoscope, without interfering with the view range of theendoscope, and to be smoothly inserted together with the endoscope intoa patient's body without injuring the patient.

Since the sheath described in Jpn. Pat. Appln. KOKOKU Publication No.4-10328 is formed as a rigid body including the transparent portion forobservation, however, the subject tissue is pressed by the sheath, sothat it is hard to observe the color and shape of the tissue accurately.In case of bleeding, moreover, the pressure exerted on the subjecttissue by the sheath makes the spot of bleeding obscure, making itdifficult to determine and perform the appropriate treatment.

According to the arrangement described in Jpn. UM Appln. KOKOKUPublication No. 4-43202, on the other hand, the endoscopic observationof tissue can be achieved through the distal opening of the sheath, sothat the subject tissue is not be pressed by the sheath. Accordingly,this sheath is not subject to the aforesaid problems. Since the sheathcannot be situated within the view range of the endoscope, however, thedegree of contact between the distal end portion of the sheath and theliving tissue cannot be detected, so that the pressure of the sheath endportion on the tissue cannot be identified. Thus, the sheath cannot besmoothly inserted into a patient's body without injuring the patient.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an endoscopic sheath,which enables a direct endoscopic observation of subcutaneous tissue orany other desired portion of a living body in which no spaces exist,facilitates accurate observation of the state of the subject tissue bymeans of an endoscope, without interfering with the view range of theendoscope, and can be smoothly inserted together with the endoscope intoa patient's body without injuring the patient.

The above object is achieved by an endoscopic sheath constructed asfollows. The endoscopic sheath comprises a tubular sheath section havinga distal end portion and a hole which extends throughout the length ofthe sheath section and through which an insert section of an endoscopehaving observation means can be passed, at least the distal end of thedistal end portion opening, and at least the distal end portion beingformed of a transparent material; and positioning means for positioningthe insert section of the endoscope in the sheath section so that atleast part of the distal end portion of the sheath section is within theview range of the endoscope.

According to the endoscopic sheath constructed in this manner, tissuesand the like can be observed through the distal opening of the tubularsheath section, so that a subject region to be observed through theopening cannot be pressed by the sheath section. Thus, the states(color, shape, etc.) of living tissue can be observed and graspedaccurately.

Since at least part of the distal end portion of the sheath sectionenters the view range of the endoscope, the state of contact between thedistal end portion of the sheath section and living tissue can berecognized with ease. Thus, the sheath section, along with theendoscope, can be smoothly inserted into a patient's body withoutinjuring it, so that the safety and reliability of surgical operationcan be improved.

In the arrangement described above, moreover, at least the distal endportion of the sheath section which enters the view range of theendoscope is formed from a transparent material in order to prevent thedistal end portion of the sheath section from interfering with the viewrange. Even when the distal end portion of the sheath section enters theview range of the endoscope, therefore, living tissue can be observedthrough the transparent portion.

If the endoscopic sheath with the aforementioned construction isinserted into subcutaneous tissue or any other organism which has nospaces therein, it pushes aside this tissue or organism, therebypositively creating a space in the region. If the endoscope is passedthrough the sheath section which is inserted in the subcutaneous tissue,for example, therefore, the subcutaneous tissue can be subjected toendoscopic observation through the distal opening or transparent portionof the sheath section.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention, and together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is a perspective view of an endoscopic sheath according to afirst embodiment of the present invention;

FIG. 2 is a longitudinal sectional view of the endoscopic sheath of FIG.1;

FIG. 3 is a front view showing an example of a monitor display of animage of an endoscope set in the endoscopic sheath of FIG. 1;

FIG. 4 is a view showing the way herniation is carried out by using theendoscopic sheath of FIG. 1;

FIG. 5 is a sectional view showing a process of herniation by means ofthe endoscopic sheath of FIG. 1;

FIG. 6 is a schematic view of a patient's body;

FIG. 7 is a sectional view taken along line 7--7 of FIG. 6;

FIG. 8 is a view showing the way appendectomy is carried out by usingthe endoscopic sheath of FIG. 1;

FIG. 9 is a view showing the way ramisection for an inferior limb iscarried out by using the endoscopic sheath of FIG. 1;

FIG. 10 is a view showing the way bolt extraction after the reduction ofa fractured articulation of a foot is carried out by using theendoscopic sheath of FIG. 1;

FIG. 11 is a sectional view showing a process of removing a bolt in thebolt extraction shown in FIG. 10;

FIG. 12 is a view showing the way augmentation mammaplasty is carriedout by using the endoscopic sheath of FIG. 1;

FIG. 13 is a sectional view showing the principal part of an endoscopicsheath according to a second embodiment of the invention;

FIG. 14 is a sectional view showing the principal part of an endoscopicsheath according to a third embodiment of the invention;

FIG. 15 is a half-sectional view showing an endoscopic sheath accordingto a fourth embodiment of the invention;

FIG. 16 is a perspective view showing an operating state of theendoscopic sheath of FIG. 15;

FIG. 17 is a perspective view of an endoscopic sheath according to afifth embodiment of the invention;

FIG. 18 is a longitudinal sectional view taken along line 18--18 of FIG.17;

FIG. 19 is a view showing a technique for smoothing the forehead byusing the endoscopic sheath of FIG. 17;

FIG. 20 is a longitudinal sectional view of an endoscopic sheathaccording to a sixth embodiment of the invention;

FIG. 21 is a side view of the proximal side of an endoscopic apparatusincluding the endoscopic sheath of FIG. 20;

FIG. 22 is an enlarged sectional view taken along line 22--22 of FIG.21;

FIG. 23A is a plan view showing a modification of a proximal-sidemounting structure of the endoscopic apparatus including the endoscopicsheath of FIG. 20;

FIG. 23B is an enlarged sectional view taken along 23B--23B of FIG. 23A;

FIG. 24 is a plan view of a sheath body of the endoscopic sheath of FIG.20;

FIG. 25 is a fragmentary view taken in the direction of arrow A in FIG.24;

FIG. 26 is a perspective view of a valve unit of the endoscopicapparatus including the endoscopic sheath of FIG. 20;

FIGS. 27A and 27B are plan views individually showing two examples ofthe way of mounting the valve unit of FIG. 26;

FIG. 28 is a sectional view of the valve unit of FIG. 26;

FIG. 29 is an enlarged sectional view taken along line 29--29 of FIG.28;

FIG. 30 is an enlarged sectional view taken along line 30--30 of FIG.28;

FIG. 31 is a longitudinal sectional view of an endoscopic sheathaccording to a seventh embodiment of the invention;

FIG. 32 is a fragmentary view taken in the direction of arrow B in FIG.31;

FIG. 33 is a view showing the way esophagectomy is carried out by usingthe endoscopic sheath of FIG. 31;

FIG. 34 is a longitudinal sectional view of an endoscopic sheathaccording to an eighth embodiment of the invention;

FIG. 35 is a fragmentary view taken in the direction of arrow C in FIG.34;

FIG. 36 is a perspective view of an endoscopic sheath according to aninth embodiment of the invention;

FIG. 37 is a longitudinal sectional view of the endoscopic sheath ofFIG. 36;

FIG. 38 is a front view showing an example of a monitor display of animage of an endoscope set in the endoscopic sheath of FIG. 36;

FIG. 39 is a front view showing another example of the monitor displayof the image of the endoscope set in the endoscopic sheath of FIG. 1;

FIG. 40 is a longitudinal sectional view of the endoscopic sheath ofFIG. 36;

FIG. 41 is another longitudinal sectional view of the endoscopic sheathof FIG. 36;

FIG. 42 is a side view, partially in section, showing a bendableendoscopic sheath;

FIG. 43 is an enlarged half-sectional view showing a section 43 shown inFIG. 42;

FIG. 44 is an enlarged half-sectional view showing a section 44 shown inFIG. 42;

FIG. 45 is a side view of an endoscopic sheath having a treatmentchannel and an endoscopic channel; and

FIG. 46 is a longitudinal sectional view of the endoscopic sheath ofFIG. 45.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments of the present invention will now be describedwith reference to the accompanying drawings.

FIGS. 1 to 10 show a first embodiment of the present invention. As shownin FIG. 1, an endoscopic sheath 1 according to the present embodimentcomprises a tubular sheath section 2 which can be inserted into apatient's body. The sheath section 2 is composed of a sheath body 2a anda transparent cap 2b attached to the distal end portion of the sheathbody 2a. The sheath body 2a is formed of a rigid hollow member, such asa stainless-steel pipe, while the transparent cap 2b is formed of atransparent material, e.g., polycarbonate.

As shown in FIG. 2, the transparent cap 2b has the shape of a hollowcylinder, and is formed integrally with a ring-shaped ridge 3 on theinner peripheral surface of the distal end portion thereof. The sheathbody 2a is fixed to the ring-shaped ridge 3 by means of an adhesiveagent or formed integrally therewith in a manner such that its distalend abuts against the side face of the ridge 3. The ring-shaped ridge 3projects inward beyond the inner surface of the sheath body 2a, and theprojecting inner surface of the ridge 3 serves as a stopper 4 whichabuts against the distal end of an insert section 11 of a rigidendoscope 10 passed through the sheath body 2a, thereby preventing thedistal end of the insert section 11 from projecting on the distal endside of the endoscope 10. The stopper 4 or the inner surface of thering-shaped ridge 3 is situated in a position such that at least part ofthe distal end portion of the transparent cap 2b is within the viewrange of the rigid endoscope 10 with the distal end of its insertsection 11 in contact with the stopper 4.

A screw section 5 is provided at the proximal end portion of the sheathbody 2a. A grip 6 can be removably screwed on the screw section 5. Anannular groove 7 is formed on the inner peripheral surface of the grip6. An O-ring 8 and a backup ring 9 are housed in the groove 7.

When the grip 6 is screwed on the sheath body 2a with a distal endportion 12 of the insert section 11 of the rigid endoscope 10 heldagainst the stopper 4 after the the insert section 11 is inserted intothe sheath body 2a, the O-ring 8 is squeezed between the grip 6 and thebackup ring 9 and projects inward. Thereupon, the insert section 11 ofthe rigid endoscope 10 is clamped by the O-ring 8 so that the sheathbody 2a and the insert section 11 are fixed in a sealed state. Thus, thestopper 4, grip 6, and O-ring 8 constitute means for positioning theinsert section 11 of the rigid endoscope 10 in the sheath section 2 sothat at least part of the distal end portion (transparent cap 2b) of thesheath section 2 is within the view range of the endoscope 10.

FIG. 3 shows a monitor 13 to which the rigid endoscope 10 is connected.According to the present embodiment, as shown in FIG. 3, the wholecircumference of the distal end edge of the transparent cap 2b isdisplayed on the monitor 13 for displaying an endoscopic image with theinsert section 11 of the endoscope 10 inserted in the sheath body 2a sothat the distal end portion 12 of the insert section 11 held against thestopper 4. Thus, the whole circumference of the distal end of the cap 2bis situated within the view range 14 of the endoscope 10.

Although the sheath body 2a and the transparent cap 2b, separate bodies,are fixed to each other according to the present embodiment, they may beformed integrally from the same material.

The following is a description of the way of carrying out herniation inan extraperitoneal approach by using the endoscopic sheath 1 and therigid endoscope 10 constructed in this manner.

As shown in FIGS. 4 and 5, the navel region of the abdominal wall 15 isincised with a knife to leave the peritoneum 16 alone. An operatorplunges his fingers into an incised region 17, and digitally detachesthe peritoneum 16 downward from the abdominal wall 15.

Then, a trocar assembly 18 is inserted into the incised region 17, andthe rigid endoscope 10 is guided into the patient's body through thebore of the assembly 18. In this case, the endoscopic sheath 1 is fittedon the insert section 11 of the endoscope 10, as shown in FIG. 2, andthe transparent cap 2b of the sheath 1 and the distal end portion of thesheath body 2a is caused to project from the distal opening of thetrocar 18. The rigid endoscope 10 is connected to a TV camera controlunit 19 and a light source unit 20, and the trocar assembly 18 isconnected to a gas feed and suction unit 21 so that a gas can be fedinto the body cavity through the assembly 18.

In this state, a gas is fed from the gas feed and suction unit 21 intothe body cavity through the trocar assembly 18 as the rigid endoscope10, fitted with the endoscopic sheath 1, is oscillated from side to sideor advanced to detach the peritoneum 16 dully from the abdominal wall 15by means of the transparent cap 2b. As the operator detaches theperitoneum 16 in this manner, he observes and checks the detached regionthrough the rigid endoscope 10 to see if there are no blood vessels orthe like in the region.

The region cleared of the peritoneum 16 is inflated by the gas fedthrough the trocar assembly 18, whereby a space for a treatment isformed. Another trocar assembly inserted from another region of theabdominal wall 15 is introduced into this space, and an instrument isinserted into the space through this second trocar assembly. When theinstrument is caused to approach a target region, a hernia sack istreated (ligated or excised) by means of the instrument under endoscopicobservation. Thereafter, the hernia sack is covered with a mesh andsutured by means of a stapler or the like, as in the case of laparotomicherniation.

Retroperitoneal internal organs, such as the kidney, adrenal glands,etc., can be delivered after the rigid endoscope 10, fitted with theendoscopic sheath 1, is introduced into the patient's body from the backside and the skin and the posterior peritoneum are detached by means ofthe transparent cap 2b to secure a cavity.

Referring now to FIGS. 6 and 7, a method of causing the rigid endoscope10, fitted with the endoscopic sheath 1 with the aforementionedconstruction, to approach the spine will be described.

FIG. 7 is a sectional view of a patient's body 250 taken along line 7--7of FIG. 6. Located behind an abdominal wall 251, as shown in FIG. 7, isan abdominal cavity 252 which is surrounded by a peritoneum 253 and aposterior peritoneum 254, and a plurality of internal organs 256 existin the abdominal cavity 252. Further, an intervertebral disk 257,articular processes 258, and a spinous process 259 exist behind theabdominal cavity 252 so as to be covered by the posterior peritoneum 254and muscles 255. In order to cause the rigid endoscope 10, fitted withthe endoscopic sheath 1, to approach the spine of the patient's body 250constructed in this manner, the rear side wall is first incised by meansof a knife. Then, the rigid endoscope 10 fitted with the endoscopicsheath 1 is guided into the patient's body through the incised region.In doing this, the posterior peritoneum 254 and the muscles 255 aredetached by means of the transparent cap 2b as the endoscope 10 iscaused to approach the intervertebral disk 257. Thereafter, a treatment,such as disk herniation, spinal fusion, or decompression of spinalcords, is conducted by means of an instrument (not shown) which is madeto extend parallel to the endoscopic sheath 1.

Referring now to FIG. 8, the way appendectomy is carried out by usingthe rigid endoscope 10 fitted with the endoscopic sheath 1 constructedin the aforementioned manner will be described. As shown in FIG. 8, thenavel region of the abdominal wall 15 is slightly incised with a knife,and the insert section 11 of the rigid endoscope 10 is inserted into apatient's body through the incised region 17. In this case, theendoscope 10 has a channel through which a forceps can be passed, andthe endoscopic sheath 1 is fitted on its insert section 11.

In this state, air from the gas feed and suction unit 21 is fed into theabdominal cavity through a gas feed tube 22 and the channel of the rigidendoscope 10, whereupon the abdominal cavity is subjected to localpneumoperitoneum. Thus, a wide view range can be secured for theendoscope 10. Then, the vermiform appendix in the abdominal cavity isdetected by means of the endoscope 10, and the basal part of thevermiform appendix is grasped by means of a grasp forceps (not shown)introduced into the abdominal cavity through the channel of theendoscope 10. In this slate, the rigid endoscope 10 is removed from theincised region 17, and the vermiform appendix is pulled out of theabdominal cavity and excised. Thereafter, the residual tissue is suturedand returned to the abdominal cavity, and the incised region 17 issutured. The grasp forceps may be introduced in parallel with the rigidendoscope 10 into the patient's body without being passed through thechannel of the endoscope 10.

Referring now to FIG. 9, the way ramisection is carried out for aninferior limb by using the rigid endoscope 10 fitted with the endoscopicsheath 1 constructed in the aforementioned manner will be described. Asshown in FIG. 9, a central portion 24 of a crus is first slightlyincised with a knife. Then, the fascia and muscles are detacheddigitally, the insert section 11 of the rigid endoscope 10 is insertedinto an incised region 25, and rami communicantes are located. In thiscase, the endoscope 10 has the channel through which a forceps can bepassed, and the endoscopic sheath 1 is fitted on the insert section 11.

When the position of the rami communicantes are located, ahigh-frequency electrode 27 connected to a high-frequency power source26 is inserted into the channel of the rigid endoscope 10, and the ramicommunicantes are cauterized and blocked by means of the electrode 26.Thereafter, the incised region 25 is closed.

Besides the excision of these nerves, blood vessels of an inferior limbmay be detached, excised, and taken out for vascular implantation. Indoing this, small bifurcated blood vessels are blocked by clipping orcauterization.

Referring now to FIGS. 10 and 11, the way a bolt used in the reductionof a fractured articulation of a foot is removed by using the rigidendoscope 10 fitted with the endoscopic sheath 1 constructed in theaforementioned manner will be described. As shown in FIG. 10, a regionnear a foot articulation 28 is first slightly incised with a knife.Then, the insert section 11 of the endoscope 10 fitted with theendoscopic sheath 1 is inserted into an incised region 29, and a forceps30 is inserted into the channel of the endoscope 10. The surroundingtissues are detached with the forceps 30 as the bolt is located by meansof the endoscope 10.

When the bolt 31 is located, as shown in FIG. 11, the transparent cap 2bof the endoscopic sheath 1 is fitted on the head of the bolt 31, thatis, the bolt head is caught in the cap 2b. In this state, the insertsection 11 of the rigid endoscope 10 is removed from the sheath body 2a,and a screwdriver 32 is inserted into the body 2a instead. The bolt 31is turned and removed from the mounting position by means of thescrewdriver 32. Thereafter, the endoscopic sheath 1, along with the bolt31, is removed from a patient's body, and the incised region 29 isclosed.

Referring now to FIG. 12, the way augmentation mammaplasty is carriedout by using the rigid endoscope 10 fitted with the endoscopic sheath 1constructed in the aforementioned manner will be described. First, aregion under the armpit is slightly incised with a knife, as shown inFIG. 12. The insert section 11 of the endoscope 10 fitted with theendoscopic sheath 1 is inserted into a patient's body through an incisedregion 33, and its view range is secured. A handle 34 is provided on theproximal side of the sheath body 2a. Then, the high-frequency electrode27 is introduced into the patient's body through the channel of therigid endoscope 10, and detachment of tissue is advanced as theelectrode 27 is used for incision and coagulation. Thereafter, animplant, such as a saline bag, is inserted into the pectoral regionthrough the incised region 33, and a physiological saline is put intothe bag to fill it out. When the incised region 33 is closed afterleaving the impregnated saline bag in the pectoral region, theaugmentation mammaplasty is completed.

With use of the endoscopic sheath 1 of the present embodiment, asdescribed above, tissues and the like can be observed through the distalopening of the cylindrical transparent cap 2b, so that a subject regionto be observed through the opening cannot be pressed by the sheathsection 2. Thus, the states (color, shape, etc.) of living tissue can beobserved and grasped accurately.

Conventionally, if no cavity is secured in a patient's body when onlythe rigid endoscope 10 is inserted into the patient's body, tissue maybe caught and upset by a view window or the like of the insert section11 of the endoscope 10, so that the treatment must inevitably beconducted substantially recklessly. According to the present embodiment,however, the rigid endoscope 10 is combined with the endoscopic sheath 1which is composed of the sheath body 2a and the transparent cap 2b onthe distal end portion thereof. Accordingly, there is no possibility ofthe transparent cap 2b entering the view range of the endoscope 10 sothat the view window of the endoscope 10 is covered or narrowed bytissue. Thus, the view range can be secured at all times, so that therigid endoscope 10 can be caused to approach the target region safelyand securely.

According to the endoscopic sheath 1 of the present embodiment,moreover, at least part of the distal end portion of the transparent cap2b enters the view range of the endoscope 10, so that the state ofcontact between the distal end portion of the cap 2b and living tissuecan be recognized with ease. Thus, the sheath section 2, along with theendoscope 10, can be smoothly inserted into the patient's body withoutinjuring it, so that the safety and reliability of the surgicaloperation can be improved.

According to the endoscopic sheath 1 of the present embodiment,furthermore, the cap 2b which enters the view range of the rigidendoscope 10 is formed from a transparent material in order to preventthe distal end portion of the cap 2b from interfering with the viewrange. Even when the distal end portion of the transparent cap 2b entersthe view range of the endoscope 10, therefore, living tissue can beobserved through the transparent portion.

If the endoscopic sheath 1 is inserted into subcutaneous tissue or anyother organism which has no spaces therein, it pushes aside this tissueor organism, thereby positively creating a space in the region. If theendoscope 10 is passed through the sheath section 2 which is inserted inthe subcutaneous tissue, for example, therefore, the subcutaneous tissuecan be subjected to endoscopic observation through the transparent cap2b or its distal opening.

As described in connection with the individual examples of surgicaloperations, the endoscopic sheath 1 according to the present embodimenthas the following effects depending on the techniques.

[Herniation of FIG. 5]

(a) Since the peritoneum 16 or the like can be detached dully by meansof the transparent cap 2b, manipulation is easy. In the case of hernia,in particular, the surroundings can be seen through the peritoneum 16during the detachment of the peritoneum, the dull detachment by means ofthe transparent cap 2b can be carried out safely.

(b) Since gap between the insert section 11 of the transparent cap 2band the sheath section 2 are sealed with the O-ring 8, the endoscopicsheath 1 can be used to perform gas feed into the patient's body orsucking operation.

[Reduction of Fracture of FIG. 11]

Since the treatment and operation can be carried out with the bolt 31 orsome other member in the transparent cap 2b, there is no possibility oftheir damaging the surrounding tissues.

[Augmentation Mammaplasty of FIG. 12]

If the handle 34 is provided on the transparent cap 2b, the sheathsection 2 can be easily moved back and forth, from side to side, and upand down, so that the treatment can be conducted smoothly.

FIG. 13 shows a second embodiment of the present invention. In thepresent embodiment, a tapered portion 42 is provided covering the wholecircumference of the distal end portion of a transparent cap 2b. Forother components, the second embodiment is constructed in the samemanner as the first embodiment. According to this arrangement, thetapered portion 42 serves further to facilitate the detachment at thedistal end of the transparent cap 2b.

FIG. 14 shows a third embodiment of the present invention. In thepresent embodiment, part of the distal end of a transparent cap 2b iscut aslant to form a slope 44. For other components, the thirdembodiment is constructed in the same manner as the first embodiment.According to this arrangement, the whole circumference of the distal endof the transparent cap 2b is covered by the view range of the endoscope10, so that the state of contact between tissue and the distal end ofthe cap 2b can be recognized at all times, thus ensuring safety. Ingeneral, an endoscope has a deviation between its center and the centerof its view range. If part of the distal end portion of the transparentcap 2b is cut aslant, as in the case of the present embodiment,interference with the view range can be minimized. If an instrument isintroduced into a patient's body through the channel of the endoscope10, in the arrangement of the present embodiment, safety can be ensuredbecause the instrument can come into contact with tissue only in theview range of the endoscope 10.

FIGS. 15 and 16 show a fourth embodiment of the present invention. Asshown in FIG. 15, an endoscopic sheath 45 according to the presentembodiment comprises a sheath section 46 which can be inserted into apatient's body. The sheath section 46 is composed of a tubular sheathbody 46a and a cylindrical transparent cap 46b attached to the distalend portion of the sheath body 46a. A grip 47 is attached to theproximal end portion of the sheath body 46a. Also, a balloon 48 isfitted on the distal end portion of the sheath body 46a, adjoining thetransparent cap 46b.

Both end portions of the balloon 48 are fastened to the sheath body 46aby means of strings. An adhesive agent is applied to the fastenedportions so that the balloon 48 is fixed to the sheath body 46a. Theside wall of the sheath body 46a is formed with an opening 49 whichfaces the balloon 48. The grip 47 is provided with a lure connector 50.The connector 50 is adapted to be connected with a tube 41 (see FIG. 16)which is connected to a gas/water feed unit 51. O-rings 54 and 55 areprovided in grooves in the inner surfaces of the transparent cap 46b andthe grip 47, respectively. When the endoscope 10 is inserted in thesheath section 46, the gap between the insert section 11 of theendoscope 10 and the sheath body 46a is sealed by the O-rings 54 and 55.

A ring-shaped ridge 3 is formed integrally on the inner peripheralsurface of the distal end portion of the transparent cap 46b. The sheathbody 46a is fixed to the ring-shaped ridge 3 by means of an adhesiveagent or formed integrally therewith in a manner such that its distalend abuts against the side face of the ridge 3. The ring-shaped ridge 3projects inward beyond the inner surface of the sheath body 46a , andthe projecting inner surface of the ridge 3 serves as a stopper 4 whichabuts against the distal end of the insert section 11 of the rigidendoscope 10 passed through the sheath body 46a, thereby preventing thedistal end of the insert section 11 from projecting on the distal endside of the endoscope 10. The stopper 4 or the inner surface of thering-shaped ridge 3 is situated in a position such that at least part ofthe distal end portion of the transparent cap 46b is within the viewrange of the rigid endoscope 10 with the distal end of its insertsection 11 in contact with the stopper 4.

In the arrangement described above, if a gas or water is supplied fromthe gas/water feed unit 51 to the lure connector 50 through the tube 41,it can be fed into the balloon 48 through the gap between the insertsection 11 of the endoscope 10 and the sheath body 46a, therebyinflating the balloon 48 (see FIG. 16). In carrying out the herniationshown in FIG. 5 from outside the peritoneum, for example, therefore, theabdominal wall 15 and the peritoneum 16 can be detached extensively at astroke from each other by inflating the balloon 48 after being detachedto some degree by means of the transparent cap 2b.

Thus, according to the endoscopic sheath 45 of the present embodiment,the same effects of the first embodiment can be produced naturally.Since the abdominal wall 15 and the peritoneum 16 can be detachedextensively at a stroke from each other, moreover, manipulation is easy,and the operating time can be shortened. When the endoscopic sheath 45is used in the abdominal cavity, furthermore, it can serve for theexclusion of surrounding tissues, thereby securing an operating fieldwide enough for smooth treatment.

FIGS. 17 to 19 show a fifth embodiment of the present invention. Asshown in FIG. 17, an endoscopic sheath 56 according to the presentembodiment comprises a sheath section 57 which can be inserted into apatient's body. The sheath section 57 is composed of a tubular sheathbody 57a and a substantially cylindrical transparent cap 57b attached tothe distal end portion of the sheath body 57a. A substantiallycylindrical receiving member 58 is attached to the proximal end portionof the sheath body 57a.

As shown in FIG. 18, the transparent cap 57b has a distal opening 60which is slanted so as to fit the view range of a skew-vision rigidendoscope 62 which is adapted to be passed through the sheath section57. The distal opening 60 is designed so that the view range of adirect-vision endoscope can be secured to some degree when it is passedthrough the sheath section 57. A sealing member 61 is provided in agroove which is formed in the inner surface of the receiving member 58.The sealing member 61 serves to maintain airtightness between the rigidendoscope 62 and the sheath body 57a.

As shown in FIGS. 17 and 18, the receiving member 58 is provided with asubstantially U-shaped snap fit 63 which has springiness. A pair ofconical projections 64 are arranged facing each other inside the snapfit 63. The distance between the projections 64 is a little shorter thanthe outside diameter of a light guide connector 65 of the rigidendoscope 62. Thus, when the endoscope 62 is inserted into the sheathbody 57a, the connector 65 comes into contact with the projections 64.When the endoscope 62 is inserted deeper into the sheath body 57a, thesnap fit 63 is widened so that the light guide connector 65 extendsbeyond the top of each projection 64. Thereupon, the snap fit 63 isrestored to its initial position by its own urging force, whereby therigid endoscope 62 is fixed to the sheath body 57a.

Formed on the inner peripheral surface of the distal end portion of thetransparent cap 57b is an engaging portion 43 against which theskew-vision rigid endoscope 62 abuts. When the endoscope 62 is fixed tothe sheath body 57a by the snap fit 63 so that the distal end of theinsert section of the endoscope 62 abuts against the engaging portion43, at least part of the open distal end portion of the transparent cap57b is located within the view range of the endoscope 62.

Referring now to FIG. 19, a technique for smoothing the forehead bymeans of the endoscopic sheath 56 constructed in the aforesaid mannerwill be described.

First, a patient's scalp 66 near the forehead is incised with a knife.Then, the scalp 66 is dully detached from a cranial bone 70 by means ofan instrument 67, such as a detachment forceps, as an incised region 68is opened to a degree such that the endoscopic sheath 56 can be insertedtherein. Thereafter, the rigid endoscope 62 fitted with the endoscopicsheath 56 is inserted into the incised region 68, while the scalp 66 isdully detached to the region near eyeballs with use of the instrument67. Then, the skin of the forehead is elevated, the flabby skin isexcised, and the remaining forehead skin and the scalp 66 are sewn uptogether. The direct-vision endoscope may be used in performing theaforementioned initial operation, while the skew-vision endoscope may beused in detaching hollow portions about the eyebrows.

According to the endoscopic sheath 56 of the present embodiment, asdescribed above, the same effects of the first embodiment can beproduced, and the rigid endoscope 62 can be fixed more easily andsecurely to the sheath body 57a, so that the treatment can be conductedsmoothly with high operativity.

FIGS. 20 to 30 show a sixth embodiment of the present invention.According to the present embodiment, as shown in FIG. 20, an endoscopicapparatus 71 comprises a rigid endoscope 72, an endoscopic sheath 70fitted on the endoscope 72, a light source unit 74 for supplyingillumination light to the endoscope 72, a valve unit 76 removablymounted on a body section 75 of the endoscope 72 in a plurality ofdirections, and a water feed unit 79 and a suction unit 80 connectedwith a water feed tube 77 and a suction tube 78, respectively, which areconnected to the valve unit 76.

The rigid endoscope 72 comprises a rigid insert section 81 formed of anelongate metallic pipe or the like, the thick body section 75 at theproximal end portion of the insert section 81, and an eyepiece section84 at the proximal end of the body section 75. A light guide (not shown)for transmitting illumination light is passed through the insert section81 of the endoscope 72. The proximal end of the light guide extends upto a light guide connector 83 on the body section 75. When the connector83 is connected to the light source unit 74 by means of a light guidecable 84, the illumination light from the unit 74 is transmitted throughthe light guide cable 84 and the light guide in the endoscope 72, and isemitted forward from a distal emission face which is attached to anillumination window (not shown) on a distal end face 81a of the insertsection 81. In this case, object light from a subject, such as anaffected part, illuminated by the illumination light is focused on afocal plane by means of an objective lens (not shown) attached to a viewwindow which is formed adjacent to the illumination window. Theresulting optical image is delivered to the proximal end side by meansof an image guide, such as a relay optical system (not shown), which ispassed through the insert section 81 of the endoscope 72, and can beobserved microscopically as an enlarged image through an eyepiece (notshown) at the eyepiece section 82.

The endoscopic sheath 70, which is removably fitted on the insertsection 81 and the body section 75 of the endoscope 72, comprises asheath section 86 and a grip 87 which are fitted on the insert section81 and the body section 75, respectively, of the endoscope 72. Thesheath section 86 is composed of a tubular sheath body 86a and acylindrical transparent cap 86b formed on the distal end of the sheathbody 86a. In this arrangement, the grip 87 is formed at the proximal endof the sheath body 86a. The transparent cap 86a is formed of atransparent material such as polycarbonate.

A line 88 is defined between the sheath body 86a and the insert section81 of the endoscope 72. On the proximal side of the line 88, the gapbetween the grip 87 and the body section 75 of the endoscope 72 issealed by means of an O-ring 89. A distal end 90 of the sheath body 86ais inwardly bent substantially at right angles, and in conjunction withthe distal end face 81a of the endoscope 72, forms a nozzle 91 on thedistal end side of the line 88.

The distal end portion of the sheath body 86a, which faces the nozzle91, is inwardly bent substantially at right angles, and its inside facesserves as a stopper 73 which abuts against the distal end of the insertsection 81 of the rigid endoscope 72 passed through the sheath body 86a,thereby preventing the distal end of the insert section 81 fromprojecting on the distal end side of the endoscope 72. When the distalend of the insert section 81 of the endoscope 72 is in contact with thestopper 73, at least part of the distal end portion of the transparentcap 86b is within the view range of the endoscope 72.

As shown in FIG. 21, the proximal end side of the line 88 in theendoscopic sheath 70 internally connects with the respective bores ofconnectors 93 and 94 on the grip 87 on the distal end side of the O-ring89. The connector 93 is removably connected with the water feed tube 77and the suction tube 78 by means of a mounting portion 95 of the valveunit 76. Out of the connectors 93 and 94 on the grip 87, the connector94 which is not connected with the mounting portion 95 is fitted with acap 96 which closes the opening of the connector 94. By operating awater feed button 97 and a suction button 98 on the valve unit 76, asmentioned later, water feed and sucking operations for the tubes 77 and78 can be started and stopped, and the flow rate of a liquid, such aswater, flowing through the tubes 77 and 78 can be regulated.

As shown in FIGS. 21 and 22, the grip 87 is provided with asubstantially U-shaped groove 103 and narrow grooves 104 and 105arranged alternately, whereby two claws 106 and 107 are formed. TheU-shaped groove 103 is composed of a wide portion 101, which has a widtha little greater than the diameter of the light guide connector 83 ofthe rigid endoscope 72, and a narrow portion 102 at the open end, whichhas a width a little smaller than the diameter of the connector 83. Whenthe insert section 81 of the endoscope 72 is inserted into the sheathbody 86a, in this arrangement, the light guide connector 83 of the rigidendoscope 72 is held between the two claws 106 and 107. Thus, theendoscope 72 can be prevented from rotating or shifting in thelongitudinal direction with respect to the endoscopic sheath 70.

Instead of forming the claws 106 and 107 on the grip 87 by means of theU-shaped groove 103 and the narrow grooves 104 and 105, a substantiallyU-shaped claw member 109 may be provided outside the grip 87, as shownin FIG. 23A or 23B.

The valve unit 76, which is removably mounted on the body section 75 ofthe endoscope 72 in a plurality of directions, is composed of a bodyportion 76a carrying the water feed button 97 and the suction button 98thereon and a substantially U-shaped mounting portion 76b which isremovably mounted on the body section 75 of the endoscope 72, as shownin FIG. 26.

When the valve unit 76 is mounted on the body section 75 of the rigidendoscope 72, it is fixedly positioned by the grip 87 of the endoscopicsheath 70. As shown in FIG. 24, a receiving portion 111 for receivingthe valve unit 76 is provided at the lower part of the proximal endportion of the grip 8. The receiving portion 111 serves to settle themounting position of the valve unit 76 and restrain the unit 76 fromshifting its position. When the mounting portion 76b of the valve unit76 is fitted on the body section 75 of the endoscope 72, both edges 113of a mounting opening 112 of the valve unit 76 get engaged with thereceiving portion 111, so that the unit 76 is restrained from rotating.In FIGS. 24 and 25, the valve unit 76 is illustrated by broken line andhatching to make its outline clear.

As shown in FIG. 24, the receiving portion 111 is provided with a pairof bisymmetrical groove portions 114. As shown in FIG. 26, moreover, aclaw 115 is formed on each end of each edge 113 of the mounting portion76b of the valve unit 76. When the valve unit 76 is mounted on the bodysection 75 of the rigid endoscope 72, according to this arrangement, twoof the four claws 115 are fitted in their corresponding groove portions114, whereby the unit 76 is restrained from moving in the axialdirection with respect to the endoscope 72.

FIG. 27A is a bottom view of the endoscope 72 having its body section 75fitted with the valve unit 76. FIG. 27B shows a state such that thevalve unit 76 is mounted in a position opposite to the position shown inFIG. 27A. Since the valve unit 76 can be thus mounted on the endoscope72 in a plurality of directions, the operator can select his desiredmounting direction.

If the pair of groove portions 114 are arranged in a plurality ofpositions with respect to the longitudinal direction of the receivingportion 111, as shown in FIG. 27, for example, the valve unit 76 can beremovably mounted any of these positions. Thus, the valve unit 76 can bemounted in any desired position and direction, so that the degree offreedom of selection of operativity can be improved.

Referring now to FIGS. 28 to 30, the respective constructions of thebody portion 76a of the valve unit 76 and the mounting portion 95 willbe described.

As shown in FIG. 28, the valve body portion 76a has a water feed port116 and a suction port 117. The ports 116 and 117 are arranged above andbelow so as to penetrate the body portion 76a horizontally. The waterfeed tube 77 and the suction tube 78 are passed through the water feedport 116 and the suction port 117, respectively.

Also, the valve body portion 76a is provided with first and secondvertical holes 118 and 119 which cross the water feed tube 77 and thesuction tube 78 so as to communicate vertically therewith and arearranged in front and in rear.

The water feed button 97 is fitted in the first vertical hole 118 forvertical movement. The button 97 is continually urged upward by a spring124 which is supported on an inwardly protruding supporting portion 120of the first vertical hole 118. As shown in FIG. 29, the water feedbutton 97 is composed of a button portion 97a and a frame-shaped backupportion 97b which extends downward from the button portion 97a andpresses the water feed tube 77 continually against the supportingportion 120. The water feed tube 77 is passed through the frame of thebackup portion 97b. In a normal state that the button portion 97a is notdepressed, the tube 77 is pressed against the lower surface of thesupporting portion 120 to be flattened by the hoisting action of thebackup portion 97b caused by the urging force of the spring 124, so thata bore (line) 126 of the tube 77 is closed.

On the other hand, the suction button 98 is fitted in the secondvertical hole 119 for vertical movement. The button 98 is continuallyurged upward by a spring 124 which is supported on an inwardlyprotruding supporting portion 122 of the second vertical hole 119.Further, a projecting portion 123 protrudes inward from that part of thesecond vertical hole 119 which is situated below the water feed port116. As shown in FIG. 30, the suction button 98 is composed of a buttonportion 98a and a frame-shaped backup portion 98b which extends downwardfrom the button portion 98a and presses the suction tube 78 continuallyagainst the projecting portion 123. The suction tube 78 is passedthrough the frame of the backup portion 98b. In a normal state that thebutton portion 98a is not depressed, the tube 78 is pressed against thelower surface of the projecting portion 123 to be flattened by thehoisting action of the backup portion 98b caused by the urging force ofthe spring 124, so that a bore (line) 127 of the tube 78 is closed.Although the water feed tube 77 is also passed through the frame of thebackup portion 98b, in this case, its bore (line) 126 is not closed bythe hoisting action of the backup portion 98b.

When the water feed button 97 is depressed against the urging force ofthe spring 124, in the arrangement described above, it moves to theposition indicated by two-dot chain line in FIG. 29. Thereupon, theforce to press the water feed tube 77 against the lower surface of thesupporting portion 120 is lessened, so that tube 77 is restored to itsoriginal tubular shape by its own elasticity. As a result, the bore 126of the water feed tube 77 opens, so that the liquid is allowed to be fedthrough the tube 77. The rate of liquid feed through the water feed tube77 can be adjusted by changing the depth of depression of the water feedbutton 97.

When the suction button 98 is depressed against the urging force of thespring 124, on the other hand, it moves to the position indicated bytwo-dot chain line in FIG. 30. Thereupon, the force to press the suctiontube 78 against the lower surface of the projecting portion 123 islessened, so that tube 78 is restored to its original tubular shape byits own elasticity. As a result, the bore 127 of the suction tube 78opens, so that the liquid is allowed to be fed through the tube 78. Alsoin this case, the rate of liquid feed through the suction tube 78 can beadjusted by changing the depth of depression of the suction button 98.

According to the endoscopic apparatus including the endoscopic sheath 70of the present embodiment, as described above, the surface of theobjective lens of the endoscope 72 can be cleaned by performing thewater feed and sucking operations through a passage which includes thetubes 77 and 78, line 88, and nozzle 91, even in case the view rangecannot be secured because the objective lens is soiled by blood or thelike which is introduced into the transparent cap 86b during thesurgical operation. If the objective lens is soiled, it isconventionally necessary to pull out the endoscope, along with thedistal cap of the endoscopic sheath, from the patient's body, clean theobjective lens of soil, and cause the endoscope to approach again to itsoriginal position (DE3743042A1, etc.). According to the arrangement ofthe present embodiment, however, the objective lens can be cleanedwithout removing the endoscope from the endoscopic sheath 70, so thatthe operating time can be shortened.

According to the present embodiment, moreover, the valve unit 76 can beremovably mounted on the body section 75 of the endoscope 72, and itsstate (direction) of attachment can be selected freely (see FIGS. 27Aand 27B). Accordingly, the operator can mount the valve unit 76 in hisdesired direction for ease of operation. In consequence, the endoscopecan be held without effort during a surgical operation which requiressubtle manipulations or many hours, and the buttons on the valve unit 76can be operated with ease. Thus, the surgical operation can be advancedsmoothly, and the operator's fatigue can be lightened.

FIGS. 31 to 33 show a seventh embodiment of the present invention. Asshown in FIGS. 31 and 32, an endoscopic sheath 150 according to thepresent embodiment comprises a sheath section 151 which can be insertedinto a patient's body. The sheath section 151 is composed of a tubularsheath body 151a and a cylindrical transparent cap 151b attached to thedistal end portion of the sheath body 151a. A grip 153 is attached tothe proximal end portion of the sheath body 151a, and an arm 154 to theproximal end portion of the transparent cap 151b.

A ring-shaped ridge 3 protrudes integrally from the inner peripheralsurface of the distal end portion of the transparent cap 151b. Thesheath body 151a is fixed to the ring-shaped ridge 3 by means of anadhesive agent or formed integrally therewith in a manner such that itsdistal end abuts against the side face of the ridge 3. The ring-shapedridge 3 projects inward beyond the inner surface of the sheath body151a, and the projecting inner surface of the ridge 3 serves as astopper 4 which abuts against the distal end of an insert section of anendoscope passed through the sheath body 151a, thereby preventing thedistal end of the insert section from projecting on the distal end sideof the endoscope. The stopper 4 or the inner surface of the ring-shapedridge 3 is situated in a position such that at least part of the distalend portion of the transparent cap 151b is within the view range of theendoscope with the distal end of its insert section in contact with thestopper 4.

The arm 154 is composed of a mounting portion 159, which is fixedlyconnected to the transparent cap 151b and the sheath body 151a, and anarm body 158 in the form of a substantially semicircular loop declinedto the proximal side with respect to the sheath body 151a. As shown inFIG. 31, the arm body 158 has a substantially elliptic cross section,and an opening 160 is provided between the arm body 158 and the mountingportion 159. The sheath body 151a has a marking 156 on its proximal sidefor indicating the direction in which the arm body 158 is situated.Thus, the operator can recognize the direction of the position of thearm body 158 on the proximal side.

The grip 153 is removably screwed on the sheath body 151a. An elasticmember 161 of silicone rubber or the like is disposed in the bore of thegrip 153. When the grip 153 is screwed onto the sheath body 151a, inthis arrangement, the elastic member 161 is squeezed so that the gapbetween the endoscopic sheath 150 and the endoscope (not shown) insertedtherein is sealed. The state of sealing between the endoscopic sheath150 and the endoscope can be changed by adjusting the depth ofengagement of the grip 153.

Referring now to FIG. 33, the way the endoscopic sheath 150 with theaforementioned construction is used for esophageal ablation inesophagectomy.

First, a patient's cervical part 161 is incised with a knife, as shownin FIG. 33. After an esophageal portion 157 around an incised region 162is digitally detached, an endoscope 163 with the endoscopic sheath 150fitted thereon is inserted into the incised region 162. At this time,the detached esophageal portion 157 is put into the loop of the arm body158 through the opening 160 of the arm 154. with the esophageal portion157 caught by the arm body 158, restiform bodies or blood vessels areexcised or clipped by means of a forceps 164 (or electrode or clip)introduced into the patient's body through a channel of the endoscope163 to advance detachment. Thus, the arm body 158 always catches thedetached esophageal portion 157.

While one operator is carrying out the above surgical operation, anotheroperator prepares a stomach tube to serve as an substitute for theesophagus after the esophagectomy, and digitally detaches the lower partof the esophageal portion 157 in a direct-vision manner. When thedetachment, excision, and evulsion of the esophageal portion 157 arefinished, the incised region 162 is closed by anastomosing the stomachtube and the excised end of the cervical part 161.

According to the endoscopic sheath 150 of the present embodiment, asdescribed above, the same effects of the first embodiment can beproduced naturally, and the detachment of the esophagus, which hasconventionally been able to be carried out only blindly and digitally,can be conducted under the observation through the endoscope, thusensuring a safe reliable surgical operation.

Since the endoscopic sheath 150 can be introduced into the patient'sbody in a manner such that the arm 154 is always guided along theesophageal portion 157, the region around the esophageal portion 157 canbe approached without missing the esophageal portion 157, so that theesophagus can be detached with ease. Thus, the surgical operation can becarried out safely and securely.

Since the arm body 158 of the endoscopic sheath 150 is declined to theproximal side, moreover, only the detached esophageal portion 157 iscaught by the arm body 158. In other words, only the detached esophagealportion 157 can enter the loop of the arm body 158. Thus, the esophagealportion 157 or its surrounding tissues cannot be carelessly damagedoutside the view range.

FIGS. 34 and 35 show an eighth embodiment of the present invention. Inan endoscopic sheath 170 according to the present embodiment, a smoothrecessed portion 172 is formed extending in the axial direction in theouter surface of a transparent cap 171. For other components, the eighthembodiment is constructed in the same manner as the seventh embodiment.

When using the endoscopic sheath 170 for the detachment of theesophageal portion 157 in esophagectomy, the sheath 170 is insertedthrough the incised region 162 (see FIG. 33) with the recessed portion172 extending along the esophageal portion 157. Then, restiform bodiesor blood vessels are treated with a forceps (or clip or otherinstrument), which is inserted in the patient's body in parallel withthe sheath 170, as the esophageal portion 157 is detached by means ofthe distal end portion of the transparent cap 171.

Thus, the endoscopic sheath 170 of the present embodiment can be guidedalong the esophageal portion 157 by the recessed portion 172 of thetransparent cap 171 as it approaches the region around the esophagealportion 157, so that the esophageal portion 157 can be detached safelyand securely.

FIGS. 36 to 41 show a ninth embodiment of the present invention. Asshown in FIG. 36, an endoscopic sheath 210 according to the presentembodiment comprises a tubular sheath section 211, having a bore 213through which an insert section 225 (see FIG. 37) of an endoscope 224can be passed, and a positioning member 212 for positioning theendoscope 224 with respect to the sheath section 211.

The sheath section 211 is formed substantially entirely of a transparentplastic material, such as polycarbonate or polystyrene. A projectingportion 221 is provided on the proximal side of the transparent sheathsection 221. A through hole with a rectangular cross section is boredthrough the projecting portion 221 in the axial direction thereof.Formed in the upper surface of the projecting portion 221 are two slits216 which communicate with the through hole 214. The slits 216 extendparallel to each other along the through hole 214 from one end of theprojecting portion 221, and terminates in the vicinity of the other endof the projecting portion 221. Accordingly, an upper surface region 221aof the projecting portion 221, which is sandwiched between the two slits216, can be deformed like a cantilever. The upper surface region 221a isformed integrally with a lug 220 which projects into the through hole214 and is adapted to engage the positioning member 212. Also, the uppersurface region 221a is formed integrally with a push member 215 whichextends in the direction opposite to the lug 220, that is, upward. Whenthe push member 215 is pushed toward the distal end, in thisarrangement, the lug 220 is lifted up.

The positioning member 212 includes a substantially U-shaped plateportion 222 which is composed of a top plate 222a, having an aperture219 in the center through which a light guide adapter 226 (see FIG. 37)of the endoscope 224 can be passed, and a pair of side plates 222b whichextend vertically downward from the opposite sides of the top plate222a. The side plates 222b are adapted to be fitted on a flange portion227 (see FIG. 37) of the endoscope 224, thereby connecting thepositioning member 212 and the endoscope 224.

An elongate engaging plate 217 extends horizontally from the top plate222a. The plate 217 extends substantially from the plate portion 222,and its upper surface is flush with that of the plate 222a. The engagingplate 217 has a width and a thickness such that it can be inserted intothe through hole 214 of the projecting portion 221. The upper surface ofthe engaging plate 217 is formed with a plurality of grooves 218 which,arranged in the longitudinal direction of the plate 217, are adapted toengage the lug 220 of the projecting portion 221.

The following is a description of the case where the endoscopic sheath210 with the above construction is used in combination with theendoscope 224.

First, the positioning member 212 is attached to the endoscope 224 byfitting the light guide adapter 226 of the endoscope 224 into theaperture 219 of the positioning member 212 and fitting the side plates222b onto the flange portion 227 of the endoscope 224, as shown in FIG.37. At this time, the engaging plate 217 is directed to the distal endof the endoscope 224. In this state, the insert section 225 of theendoscope 224 is inserted into the transparent sheath section 211, andthe engaging plate 217 is passed through the through hole 214 of theprojecting portion 221. In this case, the distal end of the endoscope224 is positioned in the sheath section 211 by the positioning member212 so that at least part of the distal end portion of the sheathsection 211 is within the view range of the endoscope 224, as shown inFIG. 37. In doing this, the operator moves the positioning member 212 tochange the position of engagement between the grooves 218 of theengaging plate 217 and the lug 220 of the projecting portion 221 whilewatching a monitor 228 (see FIGS. 38 and 39) which displays an endoscopeimage. The lug 220 can be disengaged from the grooves 218 by pressingthe push member 215 to the distal end side to deform the upper surfaceregion 221a of the projecting portion 221, as shown in FIG. 41. Thus,the engaging plate 217 can be freely moved in the through hole 214 ofthe projecting portion 221, and the position of the distal end of theendoscope 224 can be changed with ease. FIG. 38 shows a display screenof the monitor 228 which displays the distal end of the transparentsheath section 211 in the view range of the endoscope 224. If the sheathsection 211 is unnecessary, the distal end of the endoscope 224 shouldonly be caused to project from the distal opening of the sheath 211, asshown in FIG. 40. In this case, the transparent sheath section 211 isnot within the view range of the endoscope 224, so that it is notdisplayed on the display screen of the monitor 228, as shown in FIG. 39.Naturally, the endoscope 224 is fixed to the sheath section 211 as thegrooves 218 of the engaging plate 217 are in engagement with the lug 220of the projecting portion 221.

As described above, the endoscopic sheath 210 of the present embodimentcan produce the same effects of the first embodiment, and besides, itsoperativity is satisfactory since the distal end of the endoscope 224can be held in a desired position with respect to the transparent sheathsection 211. Since the endoscopic sheath 210 is formed of a singletransparent material without a cap, moreover, it can be manufactured atlow cost.

FIGS. 42 to 44 show an endoscopic sheath with an alternativeconfiguration. An endoscopic sheath 180 shown in FIG. 42 comprises asheath section 181 which can be inserted into a patient's body. Thesheath section 181 is composed of a tubular sheath body 181a and acylindrical transparent cap 181b, which is formed of a transparentmaterial, such as polycarbonate, and is fixed to the distal end portionof the sheath body 181a (see FIG. 44). A cylindrical grip 183 isattached to the proximal end portion of the sheath body 181a.

As shown in FIG. 43, two rubber valves 185 are pressed and fixed in thebore of the grip 183 by means of backup plates 186a, 186b and 186c.Thus, the airtightness of an endoscope passed through the endoscopicsheath 180 can be maintained. The sheath body 181a has a curl with apredetermined radius of curvature along the curvature of the patient'sesophageal portion 157.

In detaching the esophagus by using a combination of the endoscopicsheath 180 with the aforementioned construction and a flexible endoscope(not shown), a flexible instrument is introduced into a patient's bodythrough a treatment channel of the flexible endoscope, and the esophagusis detached by means of the flexible instrument. In doing this, theflexible endoscope may be kept projecting from the distal end of theendoscopic sheath 180.

In the endoscopic sheath 180 described above, the sheath body 181a iscurved along the curvature of the esophageal portion 157, so that theesophagus can be detached more smoothly. Since the flexible endoscopecan take any desired position in this endoscopic sheath 180, moreover,the degree of freedom of operation can be improved.

An endoscopic sheath 190 shown in FIGS. 45 and 46 comprises a sheathbody 191, a transparent cap 192 formed of a transparent material, suchas polycarbonate, acrylic resin, polystyrene, or zeonex, and fixed tothe distal end portion of the sheath body 191, and a fixing member 197at the proximal end portion of the sheath body 191.

As shown in FIG. 46, the endoscopic sheath 190 is provided with atreatment lumen 201 and an endoscopic lumen 202 which extend parallel toeach other along the sheath body 191 and the fixing member 197. Thelumina 201 and 202 join together into one lumen in the bore of thetransparent cap 192. A water feed and suction pipe 193 is slidablyinserted in and connected to the treatment lumen 201 from the distal endside thereof. Inserted in the endoscopic lumen 202 is an endoscope 195through which an instrument 196 can be passed. The treatment lumen 201may be formed at an angle to the endoscopic lumen 202. In this case, thewater feed and suction pipe 193 can be introduced securely and quicklyinto the view range of the endoscope 195.

The fixing member 197 is provided with two water feed and suctionchannels 194 which, inclined at an angle to each other, communicate withthe proximal end portion of the treatment lumen 201. The proximal end ofthe treatment lumen 201 is sealed by means of a first backup member 203and an O-ring 200 which are fixed to the fixing member 197. When asecond backup member 198 is removed from the fixing member 197, thewater feed and suction pipe 193 can be drawn out to the proximal side(in the axial direction).

At the proximal end of the endoscopic lumen 202, the fixing member 197is fitted with the second backup member 198 which has an O-ring 199 inits bore. When the second backup member 198 is screwed into the fixingmember 197, in this arrangement, the O-ring 199 is squeezed so that theendoscope 195 is fixed to the fixing member 197 in a sealed state.

The slide of the water feed and suction pipe 193 to the proximal endside is restrained as the first and second backup members 203 and 198come into contact with each other. On the other hand, the slide of thepipe 193 to the distal end side is restrained as a proximal end portion206 of the sheath and a projection 207, which is attached to the pipe193 so as to project sideways from the treatment lumen 201, come intocontact with each other.

A side hole 204 is formed in the distal end portion of the water feedand suction pipe 193. That portion of the pipe 193 which is situated onthe distal end side of the hole 204 is partially constricted to form arecessed portion 205 with a reduced diameter. The recessed portion 205allows a large quantity of water to be fed into the transparent cap 192through the side hole 204, whereby an objective lens of the endoscope195 can be washed.

According to the endoscopic sheath 190 constructed in this manner, asdescribed above, the objective lens of the endoscope 195 and thetransparent cap 192 can be washed with water which is fed into the cap192 through the side hole 204 of the water feed and suction pipe 193 incase blood or the like gets into the cap 192 to block the view range ofthe endoscope 195 during a surgical operation. Thus, the view range canbe maintained for smooth treatment at all times.

Since the recessed portion 205 at the distal end portion of the waterfeed and suction pipe 193 serves to increase the rate of water feedthrough the side hole 204, moreover, the objective lens of the endoscope195 and the cap 192 can be washed securely and quickly.

In the endoscopic sheath 190 with the aforementioned construction,furthermore, the instrument, such as the water feed and suction pipe193, is restrained from advancing and retreating or rotating, so that itcannot move unexpectedly. Thus, the instrument can be prevented fromdamaging tissue or projecting and hindering the surgical operation, sothat the safety of the operation can be ensured.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, representative devices, andillustrated examples shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A method of securing a cavity in a living body,comprising the steps of:incising a small portion of the body so as toform a small incised portion; introducing an assembly of a rigid sheathwith a rigid transparent cap and an endoscope into the small incisedportion between a first tissue and a second tissue, said rigidtransparent cap being at an end portion of the rigid sheath and saidrigid transparent cap including an opening formed at a distal endthereof for enabling direct observation to be performed by the endoscopethrough the opening; and detaching the second tissue from the firsttissue using the rigid sheath with the rigid transparent cap.
 2. Amethod according to claim 1, wherein:said first tissue comprises anabdominal wall and said second tissue comprises a peritoneum; saidincising step comprises incising a small portion of the abdominal wallof such that only the peritoneum remains for forming the small incisedportion; and said detaching step comprises detaching the abdominal wallfrom the peritoneum using the rigid sheath with the rigid transparentcap or an instrument to form a cavity between the abdominal wall and theperitoneum.
 3. A method according to claim 2, wherein:said detachingstep includes detaching the abdominal wall from the peritoneum byperforming dull detachment using the rigid sheath with the rigidtransparent cap; and the method further comprises a step of securing acavity by feeding air between the abdominal wall and the detachedperitoneum and then treating a hernia sack.
 4. The method according toclaim 3, wherein the first tissue comprises muscular tissue and thesecond tissue comprises connective tissue.
 5. The method according claim1, wherein said distal end of said rigid transparent cap is ring shaped.6. A method of securing a cavity in a living body, comprising the stepsof:incising a small portion of the body so as to form a small incisedportion; introducing an assembly of a rigid sheath with a rigidtransparent cap and an endoscope into the small incised portion betweena first tissue and a second tissue, said rigid transparent cap being atan end portion of the rigid sheath and said rigid transparent capincluding an opening formed at a distal end thereof for enabling directobservation to be performed by the endoscope through the opening; anddetaching the second tissue from the first tissue using the rigid sheathwith the rigid transparent cap and an instrument to form a cavity. 7.The method according to claim 6, wherein said distal end of said rigidtransparent cap is ring shaped.
 8. The method according to claim 6,wherein the first tissue comprise muscular tissue and the second tissuecomprises connective tissue.
 9. A method of securing a cavity in aliving body, comprising the steps of:incising a small portion of thebody so as to form a small incised portion; introducing an assembly of arigid sheath with a rigid transparent cap and an endoscope into thesmall incised portion between a first tissue and a second tissue; anddetaching the second tissue from the first tissue by moving an edge ofthe rigid transparent cap from side to side or by advancing the edge ofthe rigid transparent cap, while performing observation through theendoscope.
 10. The method according to claim 9, wherein a distal endface of the rigid transparent cap is formed to have an opening and aring shape, said opening enabling direct observation to be performedtherethrough by the endoscope.
 11. The method according to claim 9,wherein the first tissue comprises muscular tissue and the second tissuecomprises connective tissue.
 12. A method of securing a cavity in aliving body, comprising the steps of:incising a small portion of anabdominal wall of the body such that only a peritoneum remains forforming a small incised portion; introducing an assembly of a rigidsheath with a rigid transparent cap and an endoscope into the smallincised portion, said rigid transparent cap being at an end portion ofthe rigid sheath and said rigid transparent cap including an openingformed at a distal end thereof for enabling direct observation to beperformed by the endoscope through the opening; and detaching theabdominal wall from the peritoneum using the rigid sheath with the rigidtransparent cap or an instrument to form a cavity between the abdominalwall and the peritoneum.
 13. A method according to claim 12,wherein:said detaching step includes detaching the abdominal wall fromthe peritoneum by performing dull detachment using the rigid sheath withthe rigid transparent cap; and the method further comprises a step ofsecuring a cavity by feeding air between the abdominal wall and thedetached peritoneum and then treating a hernia sack.